Merge pull request #2393 from DerThorsten/fix/compare_shape_of_different_types

changed impl computed_assign st shapes of different types are supported

Author: JohanMabille

include/xtensor/xassign.hpp

@@ -13,6 +13,7 @@
 #include <algorithm>
 #include <type_traits>
 #include <utility>
+#include <functional>
 
 #include <xtl/xcomplex.hpp>
 #include <xtl/xsequence.hpp>
@@ -418,16 +419,20 @@ namespace xt
     inline void xexpression_assigner<Tag>::computed_assign(xexpression<E1>& e1, const xexpression<E2>& e2)
     {
         using shape_type = typename E1::shape_type;
+        using comperator_type = std::greater<typename shape_type::value_type>;
+
         using size_type = typename E1::size_type;
 
         E1& de1 = e1.derived_cast();
         const E2& de2 = e2.derived_cast();
 
-        size_type dim = de2.dimension();
-        shape_type shape = uninitialized_shape<shape_type>(dim);
+        size_type dim2 = de2.dimension();
+        shape_type shape = uninitialized_shape<shape_type>(dim2);
+
         bool trivial_broadcast = de2.broadcast_shape(shape, true);
 
-        if (dim > de1.dimension() || shape > de1.shape())
+        auto && de1_shape = de1.shape();
+        if (dim2 > de1.dimension() || std::lexicographical_compare(shape.begin(), shape.end(), de1_shape.begin(), de1_shape.end(), comperator_type()))
         {
             typename E1::temporary_type tmp(shape);
             base_type::assign_data(tmp, e2, trivial_broadcast);

test/CMakeLists.txt

@@ -202,6 +202,7 @@ set(XTENSOR_TESTS
     main.cpp
     test_xaccumulator.cpp
     test_xadapt.cpp
+    test_xassign.cpp
     test_xaxis_iterator.cpp
     test_xaxis_slice_iterator.cpp
     test_xbuffer_adaptor.cpp

test/test_xassign.cpp

@@ -0,0 +1,148 @@
+/***************************************************************************
+* Copyright (c) Johan Mabille, Sylvain Corlay and Wolf Vollprecht          *
+* Copyright (c) QuantStack                                                 *
+*                                                                          *
+* Distributed under the terms of the BSD 3-Clause License.                 *
+*                                                                          *
+* The full license is in the file LICENSE, distributed with this software. *
+****************************************************************************/
+
+#include "gtest/gtest.h"
+#include "xtensor/xarray.hpp"
+#include "xtensor/xtensor.hpp"
+
+#include "xtensor/xassign.hpp"
+#include "xtensor/xnoalias.hpp"
+#include "test_common.hpp"
+
+#include <type_traits>
+#include <vector>
+
+
+// a dummy shape *not derived* from std::vector but compatible
+template<class T>
+class my_vector
+{
+private:
+    using vector_type = std::vector<T>;
+public:
+    using value_type = T;
+    using size_type = typename vector_type::size_type;
+    template<class U>
+    my_vector(std::initializer_list<U> vals)
+    : m_data(vals.begin(), vals.end())
+    {
+    }
+    my_vector(const std::size_t size = 0, const T & val = T())
+    : m_data(size, val)
+    {
+    }
+    auto resize(const std::size_t size)
+    {
+        return m_data.resize(size);
+    }
+    auto size()const
+    {
+        return m_data.size();
+    }
+    auto cend()const
+    {
+        return m_data.cend();
+    }
+    auto cbegin()const
+    {
+        return m_data.cbegin();
+    }
+    auto end()
+    {
+        return m_data.end();
+    }
+    auto end()const
+    {
+        return m_data.end();
+    }
+    auto begin()
+    {
+        return m_data.begin();
+    }
+    auto begin()const
+    {
+        return m_data.begin();
+    }
+    auto empty()const
+    {
+        return m_data.empty();
+    }
+    auto & back()
+    {
+        return m_data.back();
+    }
+    const auto & back()const
+    {
+        return m_data.back();
+    }
+    auto & front()
+    {
+        return m_data.front();
+    }
+    const auto & front()const
+    {
+        return m_data.front();
+    }
+    auto & operator[](const std::size_t i)
+    {
+        return m_data[i];
+    }
+    const auto & operator[](const std::size_t i)const
+    {
+        return m_data[i];
+    }
+private:
+    std::vector<T> m_data;
+};
+
+
+namespace xt
+{
+
+    template <class T, class C_T>
+    struct rebind_container<T, my_vector<C_T>>
+    {
+        using type = my_vector<T>;
+    };
+
+    TEST(xassign, mix_shape_types)
+    {
+        {
+            // xarray like with custom shape
+            using my_xarray = xt::xarray_container<
+                std::vector<int>,
+                xt::layout_type::row_major,
+                my_vector<std::size_t>
+            >;
+
+            auto a = my_xarray::from_shape({1,3});
+            auto b = xt::xtensor<int,2>::from_shape({2,3});
+            xt::noalias(a) += b;
+            EXPECT_EQ(a.dimension(), 2);
+            EXPECT_EQ(a.shape(0), 2);
+            EXPECT_EQ(a.shape(1), 3);
+        }
+        {
+            // xarray like with custom shape
+            using my_xarray = xt::xarray_container<
+                std::vector<int>,
+                xt::layout_type::row_major,
+                my_vector<std::size_t>
+            >;
+
+            auto a = my_xarray::from_shape({3});
+            auto b = xt::xtensor<int,2>::from_shape({2,3});
+            xt::noalias(a) += b;
+            EXPECT_EQ(a.dimension(), 2);
+            EXPECT_EQ(a.shape(0), 2);
+            EXPECT_EQ(a.shape(1), 3);
+        }
+
+    }
+}